We are already using this routine in other parts of TransferNonSendable to
ensure that we look through common insts that SILGen inserts that do not change
the actual underlying actor instance that we are using. In this case, I added
support for casts, optional formation, optional extraction, existential ref
initialization.
As an example of where this came up is the following test case where we fail to
look through an init_existential_ref.
```swift
public actor MyActor {
private var intDict: [Int: Int] = [:]
public func test() async {
await withTaskGroup(of: Void.self) { taskGroup in
for (_, _) in intDict {}
await taskGroup.waitForAll() // Isolation merge failure happens here
}
}
}
```
I also added the ability to at the SIL level actual test out this merge
condition using the analysis test runner. I used this to validate that this
functionality works as expected in a precise way.
rdar://130113744
This marker protocol isn't useful for abstracting over actors and distributed
actors because it doesn't have any runtime requirements, so there's no way
to switch to the given actor. Instead, you should use `isolated (any Actor)?`
parameters, and the compiler will compute a local actor value from a
distributed actor using `DistributedActor.asLocalActor`.
I added a disable flag -disable-region-based-isolation-with-strict-concurrency
so that we do not need to update the current tests. It is only available when
asserts are enabled to ensure users cannot use it.
rdar://125918028
Not quite NFC because apparently the representation bleeds into what's
accepted in some situations where we're supposed to be warning about
conflicts and then making an arbitrary choice. But what we're doing
is nonsense, so we definitely need to break behavior here.
This is setting up for isolated(any) and isolated(caller). I tried
to keep that out of the patch as much as possible, though.
values.
Teach ActorIsolation that a `nil` isolated argument is statically nonisolated,
and a reference to GlobalActor.shared statically has global actor isolation.
This change also models arbitrary actor instance isolation using VarDecls
when possible, which allows comparing two ActorIsolation values that may
represent different actor instances. Previously, ActorIsolation was
modeled only by storing the nominal actor type and the parameter index,
so the actor isolation value for two different actors was considered
to be equal. Now, the nominal actor type is only used for isolated `self`
in cases where there is no implicit self parameter decl, such as for
stored properties.
We were missing a check for conformance to `Actor` or `DistributedActor`
when an isolated parameter's type is a generic parameter.
Previously, if you used a generic parameter constrained to just `AnyActor`,
you'd crash the compiler in LowerHopToExecutor because it doesn't know
how to obtain the executor for such a value. Since `AnyActor` has no
`unownedExecutor` requirement, there's no way to get the executor without
emitting code to do dynamic casts down to `Actor` or `DistributedActor`.
Rather than have the compiler silently emit dynamic casting, I figured
it's best to ban it. This forces people to either do the dynamic casts
themselves, or use one of the more specific types to constrain their
parameter.
For other generic parameters, we would silently treat the function
as though it is nonisolated (i.e., as if the `isolated` wasn't written
on the parameter at all).
resolves rdar://109059544
This means that:
1. In test cases where minimal is the default (swift 5 without
-warn-concurrency), I added RUN lines for targeted, complete, and complete +
sns.
2. In test cases where complete is the default (swift 6, -warn-concurrency,
specified complete with -strict-concurrency), I added a send non-sendable run
line.
In each of these cases, I added additional expected-* lines as appropriate so
the tests can compile in each mode successfully.
Isolation checking for calls had two separate implementation places:
one that looked at the declaration being called (for member
declarations) and one that worked on the actual call expression. Unify
on the latter implementation, which is more general and has access to
the specific call arguments. Improve diagnostics here somewher so we
don't regress in that area.
This refactoring shouldn't change the actual semantics, but it makes
upcoming semantic changes easier.
This covers function types, closures, and function declarations:
- only one `isolated` parameter
- no global-actor + `isolated` parameter
- no `nonisolated` + `isolated`.
all diagnostics are warnings until Swift 6
A function can be actor instance-isolated to one of its parameters.
Make sure that this is reflected in ActorIsolation, so such a function
doesn't get a different actor isolation.
When a closure has an isolated parameter, the closure itself is
isolated to that parameter. Capture this in the isolation of the
closure itself, so it is propagated to nested closures.
Fixes rdar://83733845.
The concurrency runtime now deploys back to macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, which corresponds to the 5.1 release of the stdlib.
Adjust macro usages accordingly.
When a closure is provided with a contextual type that has isolated
parameters, infer that the corresponding closure parameter is "isolated".
Fixes rdar://83732479.
By default avoid imploding params that have parameter
flags, but carve out exceptions for ownership flags,
which can be thunked, and `@_nonEphemeral` which can
be freely dropped without issue.
With the introduction of `isolated` as
a type modifier for actor types, the
parsing of a parameter regressed such
that `isolated` was no longer accepted
as an ordinary argument label. This patch
fixes that and adds a little lookahead
utility to clean-up the code that
disambiguates the uses of `isolated`
as either a label or a type modifier.
Resolves rdar://80300022
Rework the checking of actor member access to rely on "isolated" parameters
(and captures thereof) to determine whether one can synchronously access
an actor or not. This allows synchronous access via an "isolated" parameter
as a general notion, which subsumes the declaration-based "self" access.
Simplify the checking of and diagnostic reporting for actor member
access by collapsing a number of redundant diagnostics down into a
single, parameterized diagnostic with a single point of emission. This
normalizes the logic a bit.
